From EP-B-0 281 650 is known an aerosol atomiser which consists of an essentially cylindrical main body in which is arranged an atomiser nozzle for atomising an aerosol and into which projects an air supply duct for the supply of the surrounding air. The external opening of the air supply duct is closed by an inlet valve which is constructed as a one-way valve. It allows the inflow of surrounding air into the nebuliser housing when a patient inhales through a mouth piece of the aerosol atomiser but prevents the aerosol from escaping from the internal chamber of the atomiser during pauses in the breathing and in the event of the patient breathing into the aerosol atomiser during exhalation. The known inhalation therapy apparatus accordingly is constructed in such a way that the patient can breathe in any desired volume of air, limited only by the flow resistance determined by the shape of the atomiser. This flow resistance as a rule is not however of any consequence to the inspiration flow of up to 100 l/min reached by a patient.
From EP-A-0 895 788 is known a valve for providing a freely predetermined limitation of the inspiration flow, so that the patient during inhalation can breathe in without any significant flow resistance only until reaching a maximum inspiration flow (threshold value) e.g. of approximately 30 l/min. On reaching or exceeding the threshold value, the movement of the valve element provided in the inlet valve is limited to such an extent that an increased flow resistance is set up. In the inhalation therapy apparatus according to the EP-A-0 895 768 this is achieved in that opposite to the valve element provided for closing the inhalation openings there is provided a limiting element against which the valve element rests when the inspiration flow of the patient exceeds the threshold value. The valve element then closes a large part of the openings which are present in the limiting element and permits the flowing through of the breathed in surrounding air only through very much smaller openings, thus increasing the flow resistance to the inhalation. The limiting element in the inhalation therapy apparatus according to the EP-A-0 895 788 is an additional component which has to be fitted in the vicinity of the valve element, especially after each cleaning process of the inlet valve by the patient.
With this prior art in the background it is the aim of this invention to further improve the known inhalation apparatus.